Apparatus for drying granular material



Dec- 2, l952 B. s. sNow APPARATUS FOR DRYING GRANULAR MATERIAL 5 Sheets-Sheet l Filed June 12, 1948 f l H u 1 f f f f V. 1 1 v, Y, f r

W M M Dec. 2, 1952 B. s. sNow APPARATUS FOR' DRYING GRANULAR MATERIAL 3 Sheets-Sheet 2 Filed June l2. 1948 Dec. 2, 1952 B. As. sNow 2,619,738

APPARATUS FOR DRYING GRANULAR MATERIAL Filed June 12, 1948 5 Sheets-Sheet 5 Patented Dec. 2, 1952 APPARATUS FOR DRYING GRANULAR MATERIAL Barton S. Snow, Batavia, Ill., assignor to T. W.

Snow Construction Company, Inc., a corporation of Illinois Application J une 12, 1948, Serial No. 32,624

4 Claims.

This invention relates to apparatus for removing moisture from granular material, such as sand, grain, and the like, and more particularly to apparatus for drying sand for use in railway equipment, such as locomotives.

The primary object of the invention is to provide an apparatus wherein sand may be introduced at the top and permitted to flow down- Wardly as it is dried out, the rate of movement being dependent upon the amount of moisture remaining in the material. Warm air may be circulated through the apparatus and will have an opportunity to heat the granules and carry out the moisture as the granules move downwardly by gravity.

Railroads use large quantities of sand, and the sand must be screened and dried so that it will not freeze in cold weather, and will be free owing whenever needed. The present apparatus is compact, and may be mounted above a large storage bunker which holds processed sand until it is required for use.

It has been found that the angle of repose for moist sand is from 40 to 45 from horizontal, and that dry sand has an angle of repose of slightly over 32 from horizontal. The present apparatus has baffle plates disposed at an angle, so that the moist sand will tend to stick to the baille plates until it is dried sufiiciently to ilow downwardly by gravity. As it travels downwardly, the nal drying of the granules may be completed while the granules are in dispersed condition.

The apparatus is illustrated in a preferred embodiment in the accompanying drawings, in which- Figure l is a fragmentary vertical sectional view of a sand-drying unit; Fig. 2, a fragmentary front elevational View, partly in section; Fig. 8, a top plan View partly in section; and Fig. 4, a fragmentary sectional view, taken as indicated at line 4 4 of Fig. 1.

In the embodiment illustrated, a material holding housing 5 is supported in an inclined position on a closed steel plate structure 6 resting on supporting channels l. An opening S is provided at the top of the housing for receiving moist sand from a large hopper 9. Beneath the housing 5 is an inclined chute IB which directs treated sand through a discharge opening I I provided in the bottom of the structure 6.

A series of parallel baffle plates I2 are supported on the structure 5, at their ends, by means of angle irons I3. Their central portion is supported by a pair of narrow longitudinally ex- 2 tending plates I4 which are welded to the chut IG. The lower end of the chute Ill is supported on four upwardly extending angle bars I5 which rest on the base I 6 of the structure. As best shown in Fig. 4, a pair of inclined plates II are provided to direct sand flowing down the chute IB into the opening II. A space is provided between the members I'I and the base I6, so that heated air may travel around the discharge opening II. The plates are held in proper angular position by means of a pair of top bars I8 and a pair of bottom bars I9.

If the apparatus is to be used for drying sand, the plates I2 preferably are disposed at an angle of approximately 30 from horizontal. As shown in the drawings, the top openings 20 between the plates are offset from the openings 2| at the bottom of the plates, so that sand may not drop vertically between the plates.

Hot air may be introduced through the opening 22 provided in the bottom of the structure, and will heat the lower side of the chute II), travel around the sand conduit I I and up through the chute through the discharge conduit 23. The lower sides of the plates I2 are also exposed to the hot air, and the air also is free to circulate over the surface of the sand resting on the plates and about the dispersed granules as they drop through the openings 2l to the discharge opening II.

If desired, an oil burning heating unit or steam unit heater 24 may be provided, to furnish heat to be circulated through the structure 6.

As shown in Figs. 1 and 2, openings 25 will be provided to the chute, and these may be closed by suitable covers 2S pivotally supported at 21. An opening 28, in the same manner, may be closed by a cover member 29.

In operation, moist sand is fed into the housing from the bunker 9, and will drop through the openings 2Q onto the plates I2. As the angle of repose of the Wet sand is greater than the angle of the plates I2, it will remain on the plates until it is sufficiently dry to flow down into the chute. If any of the sand is not completely dry, the dispersed granules are still subjected to the current of hot air which has the highest temperature and carries the least amount of moisture at the lower end of the chute, and by the time the sand leaves the discharge opening II it is thoroughly dry and ready for use.

The foregoing detailed description is given for clearness of understanding only, and no unneccessary limitations should be understood therefrom, for some modifications will be obvious to those skilled in the art.

I claim:

1. Apparatus for drying moist sand, comprising, a housing having front, rear, two side and a top wall, the front wall being higher than the rear wall, a chute leading from the front wall and inclined downwardly and rearwardly and stopping short of the rear wall, upwardly extending partition walls connecting the top side of the chute with the top wall of the housing which together w-ith the side and top walls form a moist sand compartment, a series of baffle plates positie-ned edgewise across the top of said chute, said series being inclined upwardly and forwardly between said partition walls, said baile plates being substantially parallel with each other and inclined forwardly and downwardly, said top wall being formed with an air outlet opening, said housing also having passageways for leading heated air from beneath the chute to the lower end of the chute then upwardly at an-inclination along the upper side of the chute below the baffles to said outlet opening. 5

2. Apparatus for drying granular material having a greater angle of repose when wet than when dry, comprising: a material holding housing into which moist granular material may be introduced at the top; a series of substantially parallel imperforate baie plates in said housing each disposed edgewise at an angle from horizontal which is substantially less than the angle of repose for moist material to be handled and slightly less than the angle of repose for the same material when dry, said plates each being spaced from the next adjacent plate and forming spaces between the plates open at the top and bottom so that the. bottom openings between the plates are offset from the Vertical plate at the top openings; an inclined chute extending crosswise beneath said plates for directing material owing between the plates to a point of discharge, said series of baille plates and chute being inclined to horizontal with the individual baiiie plates oppositely inclined to the inclination of the chute; and air conduits for conducting heated air through said housing and about sand flowing from said plates, said series of baiies being spaced from the chute to provide an air conduit therebetween having a discharge opening at the top separate from the material holding housing.

3. Apparatus for drying moist sand, comprising,

a housing having front, rear, two sides and a top wall, a chute leading from the front wall and inclined downwardly and rearwardly and stopping short of the rear wall, upwardly extending partition walls connecting the top side of the chute with the top wall of the housing which together with the side and top walls form a moist sand compartment, a series of bafle plates positioned edgewise across the top of said chute, said series being inclined upwardly and forwardly between said partition walls, said baflie plates being substantially parallel with each other and inclined forwardly and downwardly, means forming an air outlet opening near the upper end of the chute, said housing having passageways for leading heated air from beneath the chute to the lower end of the chute then upwardly between the chute and baiiles to the outlet opening.

4. Apparatus for drying moist sand, comprising: a housing having a bottom and upwardly extending side walls; partition walls extending downwardly from the side walls above the bottom and dividing the interior of the housing into an upper sand compartment and a lower heated air compartment; a passageway for heated air passing upwardly past the sand compartment; a dry sandcollecting chute, and a dividing wall between the chute and sand compartment provided with a series of substantially parallel bafe plates each inclined downwardly at an angle to hold moist sand in the sand compartment and to permit dry sand topass to the chute, said heated air passageway directing heated air past the lower edges of the baflie plates to dry the sand thereon, and an outlet for heated air at the upper end of the air passageway.

BARTON S. SNOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 49,470 Chichester Aug. 15, 1865 277,686 Cutler May 15, 1883 1,787,280 Nagel Dec. 30, 1930 1,823,895 Gray Sept. 22, 1931 2,118,334 Wilson May 24, 1938 

